Let’s talk about the process of the ammonia synthesis tower you use.

The first inlet gas flows down from the annular gap between the outer cylinder and the inner parts of the synthesis tower to the bottom of the synthesis tower. It comes out from the bottom of the synthesis tower inlet gas heat exchanger. After exchanging heat with the waste boiler outlet gas, it enters the second synthesis tower. It exchanges heat with the reacted gas from the bottom and exits from the center tube of the inner parts. It goes up to a height of zero meters and enters the catalyst bed. After axially moving down two stages of catalyst, the fish scale plate of the three-stage gas separator reacts radially from the outside to the inside, and then reacts from the inside to the outside at the fourth stage. After that, it exchanges heat with the second inlet gas and exits the synthesis tower.

Ours is a Kellogg process. The synthesis gas enters the annulus of the synthesis tower, cools the pressure-bearing shell and is heated. After reaching the top of the synthesis tower, it enters the internal heat exchanger of the synthesis tower to exchange heat with the reaction gas exiting the synthesis tower. Then it enters a catalyst layer, passes through the bed in the radial direction of the axis, and then enters the second and third stage beds in sequence. At the inlet of each bed section, a cold shock tube is added to introduce cold synthesis gas to adjust the temperature of the bed inlet of each section. The reacted gases are collected into the central tube from bottom to top, and then enter the internal heat exchanger at the top of the synthesis tower to exchange heat before leaving the synthesis tower.

Our ammonia synthesis tower is a neck-to-neck tower, and the gas along the way is the tower wall gas.； Along the way is the No. 2 cold shock gas, which enters from the top of the tower and cools the third-layer catalyst. ； All the way is the square cylinder cooler, which enters from the bottom of the tower ； After entering the heat exchanger all the way, it comes out and enters the tower in three ways. One is the auxiliary line gas, which enters from the top of the tower to cool the first layer of catalyst. The other is the No. 1 cold quench gas, which enters the intermediate heat exchanger from the top of the tower. After exiting the heat exchanger, it goes upwards into the first layer of catalyst frame to cool the second layer of catalyst. The main line gas enters from the bottom of the tower, merges with the tower wall and square cylinder gas, enters the lower heat exchanger, exchanges heat with the gas coming out of the catalyst box, goes up the central tube, mixes with the auxiliary line gas and the gas leaving the intermediate heat exchanger, enters the first layer of catalyst box for reaction, comes out, enters the intermediate heat exchanger, exchanges heat with the No. 1 cold shock gas, then enters the second layer of catalyst box for reaction, and then enters the third layer of catalyst box for reaction. The gas leaving the catalyst box enters the lower heat exchanger for heat exchange and then exits the tower.

Studying recently* A set of 100,000 T/Y ammonia synthesis unit. The synthesis tower adopts Casari shaft radial technology. It has two internal heat exchangers, air inlet at the bottom and air outlet at the bottom. The gas flow in the three-stage bed synthesis catalyst frame is as follows: The main airflow enters the synthesis tower through the inlet nozzle "A" at the bottom of the synthesis tower. The syngas entering from the bottom goes upward along the outer cylinder of the catalyst frame and the inner annular wall of the synthesis tower (this design can keep the temperature of the outer wall of the inner parts of the synthesis tower almost equal to the temperature of the syngas inlet). At the top of the catalyst frame, the syngas coming up from the annular gap enters the central tube with an annular opening, then goes down the central tube, and upward at the bottom of the central tube enters the second interior installed at the center of the second section of catalyst layer. On the shell side of the heat exchanger, the fresh syngas is heated by the outlet gas of the second-stage catalyst in this heat exchanger. The fresh gas temperature at the outlet of the internal exchanger is controlled by the bypass of the inlet pipeline of the synthesis tower (nozzle C1). At the same time, the inlet temperature of the second-stage bed is also controlled. Then, the fresh syngas enters the shell side of the internal heat exchanger set at the center of the first-stage bed, and the fresh syngas is continued to be heated by the outlet gas of the first-stage bed. The inlet temperature of one stage of the bed is controlled by bypassing the inlet pipeline of the synthesis tower (nozzle C2). In this way, the continuously heated fresh synthesis gas enters the first stage of the bed (in both axial and radial directions). The synthesis gas leaving the first stage of the bed enters the shell side of the internal heat exchanger for heat exchange and cooling. The cooled synthesis gas enters the second stage of the bed for ammonia synthesis reaction. The syngas leaving the second stage enters the shell side of the internal heat exchanger. After heat exchange and cooling, it enters the third-degree bed for the final reaction. The reaction gas leaving the three-stage bed gathers at the outlet and leaves the synthesis tower through nozzle B.

The synthesis tower we use is Casari axis radial technology, with an internal heat exchanger, air inlet at the bottom and air outlet at the bottom, and two catalyst beds. The gas flow in the synthesis tower is as follows: The main airflow enters from the bottom of the synthesis tower. The syngas entering from the bottom goes upward along the outer cylinder of the catalyst frame and the inner annular wall of the synthesis tower. At the top of the catalyst frame, the syngas coming up from the annular gap enters the central tube with an annular opening. Then it goes down the central tube and upwards from the bottom of the central tube into the internal heat exchanger tube installed at the center of the first section of the catalyst layer. In this heat exchanger, the fresh syngas is heated by the catalyst outlet gas. The temperature of the fresh gas at the outlet of the internal exchanger is normal. It is controlled by bypassing the inlet pipeline of the synthesis tower to control the inlet temperature of one stage of the bed. The ultimate goal is to control the temperature of one stage of the bed. The fresh synthesis gas enters the first stage of the catalyst bed after the internal heat exchanger tube side. After the reaction, the gas enters the internal heat exchanger shell side. After exchanging heat with the inlet gas, it enters the second stage of the catalyst bed. After the gas reacts in the second catalyst bed, it leaves the synthesis tower from the center of the second catalyst bed. The gas exiting the synthesis tower is about 430 degrees, so the heat recovery is better.